Structural perturbations in immersed granular beds due to shear-flow-driven erosion in a laboratory flume

Thursday, 18 December 2014
Julia C Salevan1, Mark D Shattuck2, Corey Ohern1 and Nicholas T Ouellette1, (1)Yale University, Mechanical Engineering and Materials Science, New Haven, CT, United States, (2)CUNY City College, New York, NY, United States
Our understanding of the detailed physical mechanisms that underlie erosion remains limited due to the complexity of the coupling between hydrodynamic shear, sediment transport, internal granular bed rearrangement, and bedform dynamics. In particular, it is unclear how the internal bed structure, including grain rearrangements, jamming, and force networks, affects bedform evolution and sediment transport. To address these questions, we perform experimental studies of shear flow across model granular beds in a recirculating laboratory flume. We monitor changes in the contour of the granular bed surface and in structural properties of the internal granular packing, and we examine the effects of varied fluid flow regimes and time scales on bed rearrangements.